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cc584b21 |
| 01-Sep-2008 |
Arjan van de Ven <arjan@linux.intel.com> |
hrtimer: convert kernel/* to the new hrtimer apis In order to be able to do range hrtimers we need to use accessor functions to the "expire" member of the hrtimer struct. This patch
hrtimer: convert kernel/* to the new hrtimer apis In order to be able to do range hrtimers we need to use accessor functions to the "expire" member of the hrtimer struct. This patch converts kernel/* to these accessors. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
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56c7426b |
| 01-Sep-2008 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
sched_clock: fix NOHZ interaction If HLT stops the TSC, we'll fail to account idle time, thereby inflating the actual process times. Fix this by re-calibrating the clock against GTOD whe
sched_clock: fix NOHZ interaction If HLT stops the TSC, we'll fail to account idle time, thereby inflating the actual process times. Fix this by re-calibrating the clock against GTOD when leaving nohz mode. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
3c4fbe5e |
| 20-Aug-2008 |
Miao Xie <miaox@cn.fujitsu.com> |
nohz: fix wrong event handler after online an offlined cpu On the tickless system(CONFIG_NO_HZ=y and CONFIG_HIGH_RES_TIMERS=n), after I made an offlined cpu online, I found this cpu's ev
nohz: fix wrong event handler after online an offlined cpu On the tickless system(CONFIG_NO_HZ=y and CONFIG_HIGH_RES_TIMERS=n), after I made an offlined cpu online, I found this cpu's event handler was tick_handle_periodic, not tick_nohz_handler. After debuging, I found this bug was caused by the wrong tick mode. the tick mode is not changed to NOHZ_MODE_INACTIVE when the cpu is offline. This patch fixes this bug. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
b845b517 |
| 08-Aug-2008 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
printk: robustify printk Avoid deadlocks against rq->lock and xtime_lock by deferring the klogd wakeup by polling from the timer tick. Signed-off-by: Peter Zijlstra <a.p.zijlstr
printk: robustify printk Avoid deadlocks against rq->lock and xtime_lock by deferring the klogd wakeup by polling from the timer tick. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Revision tags: v2.6.27-rc1, v2.6.26, v2.6.26-rc9, v2.6.26-rc8, v2.6.26-rc7, v2.6.26-rc6, v2.6.26-rc5, v2.6.26-rc4, v2.6.26-rc3, v2.6.26-rc2, v2.6.26-rc1, v2.6.25 |
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#
e4e4e534 |
| 14-Apr-2008 |
Ingo Molnar <mingo@elte.hu> |
sched clock: revert various sched_clock() changes Found an interactivity problem on a quad core test-system - simple CPU loops would occasionally delay the system un an unacceptable way.
sched clock: revert various sched_clock() changes Found an interactivity problem on a quad core test-system - simple CPU loops would occasionally delay the system un an unacceptable way. After much debugging with Peter Zijlstra it turned out that the problem is caused by the string of sched_clock() changes - they caused the CPU clock to jump backwards a bit - which confuses the scheduler arithmetics. (which is unsigned for performance reasons) So revert: # c300ba2: sched_clock: and multiplier for TSC to gtod drift # c0c8773: sched_clock: only update deltas with local reads. # af52a90: sched_clock: stop maximum check on NO HZ # f7cce27: sched_clock: widen the max and min time This solves the interactivity problems. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mike Galbraith <efault@gmx.de>
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#
ecc8b655 |
| 24-Jul-2008 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux
Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: nohz: adjust tick_nohz_stop_sched_tick() call of s390 as well nohz: prevent tick stop outside of the idle loop
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#
9b610fda |
| 18-Jul-2008 |
Ingo Molnar <mingo@elte.hu> |
Merge branch 'linus' into timers/nohz
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b8f8c3cf |
| 18-Jul-2008 |
Thomas Gleixner <tglx@linutronix.de> |
nohz: prevent tick stop outside of the idle loop Jack Ren and Eric Miao tracked down the following long standing problem in the NOHZ code: scheduler switch to idle task
nohz: prevent tick stop outside of the idle loop Jack Ren and Eric Miao tracked down the following long standing problem in the NOHZ code: scheduler switch to idle task enable interrupts Window starts here ----> interrupt happens (does not set NEED_RESCHED) irq_exit() stops the tick ----> interrupt happens (does set NEED_RESCHED) return from schedule() cpu_idle(): preempt_disable(); Window ends here The interrupts can happen at any point inside the race window. The first interrupt stops the tick, the second one causes the scheduler to rerun and switch away from idle again and we end up with the tick disabled. The fact that it needs two interrupts where the first one does not set NEED_RESCHED and the second one does made the bug obscure and extremly hard to reproduce and analyse. Kudos to Jack and Eric. Solution: Limit the NOHZ functionality to the idle loop to make sure that we can not run into such a situation ever again. cpu_idle() { preempt_disable(); while(1) { tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we are in the idle loop while (!need_resched()) halt(); tick_nohz_restart_sched_tick(); <- disables NOHZ mode preempt_enable_no_resched(); schedule(); preempt_disable(); } } In hindsight we should have done this forever, but ... /me grabs a large brown paperbag. Debugged-by: Jack Ren <jack.ren@marvell.com>, Debugged-by: eric miao <eric.y.miao@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
1e094813 |
| 15-Jul-2008 |
Ingo Molnar <mingo@elte.hu> |
Merge branch 'linus' into core/softlockup Conflicts: kernel/softlockup.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
da6e88f4 |
| 15-Jul-2008 |
Linus Torvalds <torvalds@linux-foundation.org> |
Merge branch 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
Merge branch 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: add PCI ID for 6300ESB force hpet x86: add another PCI ID for ICH6 force-hpet kernel-paramaters: document pmtmr= command line option acpi_pm clccksource: fix printk format warning nohz: don't stop idle tick if softirqs are pending. pmtmr: allow command line override of ioport nohz: reduce jiffies polling overhead hrtimer: Remove unused variables in ktime_divns() hrtimer: remove warning in hres_timers_resume posix-timers: print RT watchdog message
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#
af52a90a |
| 07-Jul-2008 |
Steven Rostedt <rostedt@goodmis.org> |
sched_clock: stop maximum check on NO HZ Working with ftrace I would get large jumps of 11 millisecs or more with the clock tracer. This killed the latencing timings of ftrace and also
sched_clock: stop maximum check on NO HZ Working with ftrace I would get large jumps of 11 millisecs or more with the clock tracer. This killed the latencing timings of ftrace and also caused the irqoff self tests to fail. What was happening is with NO_HZ the idle would stop the jiffy counter and before the jiffy counter was updated the sched_clock would have a bad delta jiffies to compare with the gtod with the maximum. The jiffies would stop and the last sched_tick would record the last gtod. On wakeup, the sched clock update would compare the gtod + delta jiffies (which would be zero) and compare it to the TSC. The TSC would have correctly (with a stable TSC) moved forward several jiffies. But because the jiffies has not been updated yet the clock would be prevented from moving forward because it would appear that the TSC jumped too far ahead. The clock would then virtually stop, until the jiffies are updated. Then the next sched clock update would see that the clock was very much behind since the delta jiffies is now correct. This would then jump the clock forward by several jiffies. This caused ftrace to report several milliseconds of interrupts off latency at every resume from NO_HZ idle. This patch adds hooks into the nohz code to disable the checking of the maximum clock update when nohz is in effect. It resumes the max check when nohz has updated the jiffies again. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
857f3fd7 |
| 11-Jul-2008 |
Heiko Carstens <heiko.carstens@de.ibm.com> |
nohz: don't stop idle tick if softirqs are pending. In case a cpu goes idle but softirqs are pending only an error message is printed to the console. It may take a very long time until t
nohz: don't stop idle tick if softirqs are pending. In case a cpu goes idle but softirqs are pending only an error message is printed to the console. It may take a very long time until the pending softirqs will finally be executed. Worst case would be a hanging system. With this patch the timer tick just continues and the softirqs will be executed after the next interrupt. Still a delay but better than a hanging system. Currently we have at least two device drivers on s390 which under certain circumstances schedule a tasklet from process context. This is a reason why we can end up with pending softirqs when going idle. Fixing these drivers seems to be non-trivial. However there is no question that the drivers should be fixed. This patch shouldn't be considered as a bug fix. It just is intended to keep a system running even if device drivers are buggy. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Glauber <jan.glauber@de.ibm.com> Cc: Stefan Weinhuber <wein@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
7a14ce1d |
| 12-May-2008 |
Ingo Molnar <mingo@elte.hu> |
nohz: reduce jiffies polling overhead Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
02ff3755 |
| 12-May-2008 |
Ingo Molnar <mingo@elte.hu> |
softlockup: fix false positives on nohz if CPU is 100% idle for more than 60 seconds Fix (probably theoretical only) rq->clock update bug: in tick_nohz_update_jiffies() [which is called
softlockup: fix false positives on nohz if CPU is 100% idle for more than 60 seconds Fix (probably theoretical only) rq->clock update bug: in tick_nohz_update_jiffies() [which is called on all irq entry on all cpus where the irq entry hits an idle cpu] we call touch_softlockup_watchdog() before we update jiffies. That works fine most of the time when idle timeouts are within 60 seconds. But when an idle timeout is beyond 60 seconds, jiffies is updated with a jump of more than 60 seconds, which causes a jump in cpu-clock of more than 60 seconds, triggering a false positive. Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
126e01bf |
| 24-Apr-2008 |
Ingo Molnar <mingo@elte.hu> |
softlockup: fix NOHZ wakeup David Miller reported: |---------------> the following commit: | commit 27ec4407790d075c325e1f4da0a19c56953cce23 | Author: Ingo Molnar <
softlockup: fix NOHZ wakeup David Miller reported: |---------------> the following commit: | commit 27ec4407790d075c325e1f4da0a19c56953cce23 | Author: Ingo Molnar <mingo@elte.hu> | Date: Thu Feb 28 21:00:21 2008 +0100 | | sched: make cpu_clock() globally synchronous | | Alexey Zaytsev reported (and bisected) that the introduction of | cpu_clock() in printk made the timestamps jump back and forth. | | Make cpu_clock() more reliable while still keeping it fast when it's | called frequently. | | Signed-off-by: Ingo Molnar <mingo@elte.hu> causes watchdog triggers when a cpu exits NOHZ state when it has been there for >= the soft lockup threshold, for example here are some messages from a 128 cpu Niagara2 box: [ 168.106406] BUG: soft lockup - CPU#11 stuck for 128s! [dd:3239] [ 168.989592] BUG: soft lockup - CPU#21 stuck for 86s! [swapper:0] [ 168.999587] BUG: soft lockup - CPU#29 stuck for 91s! [make:4511] [ 168.999615] BUG: soft lockup - CPU#2 stuck for 85s! [swapper:0] [ 169.020514] BUG: soft lockup - CPU#37 stuck for 91s! [swapper:0] [ 169.020514] BUG: soft lockup - CPU#45 stuck for 91s! [sh:4515] [ 169.020515] BUG: soft lockup - CPU#69 stuck for 92s! [swapper:0] [ 169.020515] BUG: soft lockup - CPU#77 stuck for 92s! [swapper:0] [ 169.020515] BUG: soft lockup - CPU#61 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#85 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#101 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#109 stuck for 92s! [swapper:0] [ 169.112554] BUG: soft lockup - CPU#117 stuck for 92s! [swapper:0] [ 169.171483] BUG: soft lockup - CPU#40 stuck for 80s! [dd:3239] [ 169.331483] BUG: soft lockup - CPU#13 stuck for 86s! [swapper:0] [ 169.351500] BUG: soft lockup - CPU#43 stuck for 101s! [dd:3239] [ 169.531482] BUG: soft lockup - CPU#9 stuck for 129s! [mkdir:4565] [ 169.595754] BUG: soft lockup - CPU#20 stuck for 93s! [swapper:0] [ 169.626787] BUG: soft lockup - CPU#52 stuck for 93s! [swapper:0] [ 169.626787] BUG: soft lockup - CPU#84 stuck for 92s! [swapper:0] [ 169.636812] BUG: soft lockup - CPU#116 stuck for 94s! [swapper:0] It's simple enough to trigger this by doing a 10 minute sleep after a fresh bootup then starting a parallel kernel build. I suspect this might be reintroducing a problem we've had and fixed before, see the thread: http://marc.info/?l=linux-kernel&m=119546414004065&w=2 <---------------| touch the softlockup watchdog when exiting NOHZ state - we are obviously not locked up. Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
d0b27fa7 |
| 19-Apr-2008 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth t
sched: rt-group: synchonised bandwidth period Various SMP balancing algorithms require that the bandwidth period run in sync. Possible improvements are moving the rt_bandwidth thing into root_domain and keeping a span per rt_bandwidth which marks throttled cpus. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Revision tags: v2.6.25-rc9, v2.6.25-rc8, v2.6.25-rc7, v2.6.25-rc6, v2.6.25-rc5, v2.6.25-rc4 |
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#
903b8a8d |
| 28-Feb-2008 |
Karsten Wiese <fzu@wemgehoertderstaat.de> |
clockevents: optimise tick_nohz_stop_sched_tick() a bit Call ts = &per_cpu(tick_cpu_sched, cpu); and cpu = smp_processor_id(); once instead of twice.
clockevents: optimise tick_nohz_stop_sched_tick() a bit Call ts = &per_cpu(tick_cpu_sched, cpu); and cpu = smp_processor_id(); once instead of twice. No functional change done, as changed code runs with local irq off. Reduces source lines and text size (20bytes on x86_64). [ akpm@linux-foundation.org: Build fix ] Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
a7901766 |
| 04-Mar-2008 |
Karsten Wiese <fzu@wemgehoertderstaat.de> |
time: don't touch an offlined CPU's ts->tick_stopped in tick_cancel_sched_timer() Silences WARN_ONs in rcu_enter_nohz() and rcu_exit_nohz(), which appeared before caused by (repeated) ca
time: don't touch an offlined CPU's ts->tick_stopped in tick_cancel_sched_timer() Silences WARN_ONs in rcu_enter_nohz() and rcu_exit_nohz(), which appeared before caused by (repeated) calls to: $ echo 0 > /sys/devices/system/cpu/cpu1/online $ echo 1 > /sys/devices/system/cpu/cpu1/online Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de> Cc: johnstul@us.ibm.com Cc: Rafael Wysocki <rjw@sisk.pl> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
2232c2d8 |
| 29-Feb-2008 |
Steven Rostedt <rostedt@goodmis.org> |
rcu: add support for dynamic ticks and preempt rcu The PREEMPT-RCU can get stuck if a CPU goes idle and NO_HZ is set. The idle CPU will not progress the RCU through its grace period and
rcu: add support for dynamic ticks and preempt rcu The PREEMPT-RCU can get stuck if a CPU goes idle and NO_HZ is set. The idle CPU will not progress the RCU through its grace period and a synchronize_rcu my get stuck. Without this patch I have a box that will not boot when PREEMPT_RCU and NO_HZ are set. That same box boots fine with this patch. This patch comes from the -rt kernel where it has been tested for several months. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Revision tags: v2.6.25-rc3, v2.6.25-rc2, v2.6.25-rc1 |
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#
cf4fc6cb |
| 08-Feb-2008 |
Li Zefan <lizf@cn.fujitsu.com> |
timekeeping: rename timekeeping_is_continuous to timekeeping_valid_for_hres Function timekeeping_is_continuous() no longer checks flag CLOCK_IS_CONTINUOUS, and it checks CLOCK_SOURCE_VAL
timekeeping: rename timekeeping_is_continuous to timekeeping_valid_for_hres Function timekeeping_is_continuous() no longer checks flag CLOCK_IS_CONTINUOUS, and it checks CLOCK_SOURCE_VALID_FOR_HRES now. So rename the function accordingly. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
5df7fa1c |
| 01-Feb-2008 |
Thomas Gleixner <tglx@linutronix.de> |
tick-sched: add more debug information To allow better diagnosis of tick-sched related, especially NOHZ related problems, we need to know when the last wakeup via an irq happened and
tick-sched: add more debug information To allow better diagnosis of tick-sched related, especially NOHZ related problems, we need to know when the last wakeup via an irq happened and when the CPU left the idle state. Add two fields (idle_waketime, idle_exittime) to the tick_sched structure and add them to the timer_list output. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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#
6378ddb5 |
| 30-Jan-2008 |
Venki Pallipadi <venkatesh.pallipadi@intel.com> |
time: track accurate idle time with tick_sched.idle_sleeptime Current idle time in kstat is based on jiffies and is coarse grained. tick_sched.idle_sleeptime is making some attempt to ke
time: track accurate idle time with tick_sched.idle_sleeptime Current idle time in kstat is based on jiffies and is coarse grained. tick_sched.idle_sleeptime is making some attempt to keep track of idle time in a fine grained manner. But, it is not handling the time spent in interrupts fully. Make tick_sched.idle_sleeptime accurate with respect to time spent on handling interrupts and also add tick_sched.idle_lastupdate, which keeps track of last time when idle_sleeptime was updated. This statistics will be crucial for cpufreq-ondemand governor, which can shed some conservative gaurd band that is uses today while setting the frequency. The ondemand changes that uses the exact idle time is coming soon. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
b10db7f0 |
| 30-Jan-2008 |
Pavel Machek <pavel@ucw.cz> |
time: more timer related cleanups I was confused by FSEC = 10^15 NSEC statement, plus small whitespace fixes. When there's copyright, there should be GPL. Signed-off-by: Pavel M
time: more timer related cleanups I was confused by FSEC = 10^15 NSEC statement, plus small whitespace fixes. When there's copyright, there should be GPL. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
4c9dc641 |
| 30-Jan-2008 |
Pavel Machek <pavel@ucw.cz> |
time: timer cleanups Small cleanups to tick-related code. Wrong preempt count is followed by BUG(), so it is hardly KERN_WARNING. Signed-off-by: Pavel Machek <pavel@suse.cz>
time: timer cleanups Small cleanups to tick-related code. Wrong preempt count is followed by BUG(), so it is hardly KERN_WARNING. Signed-off-by: Pavel Machek <pavel@suse.cz> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
2d44ae4d |
| 25-Jan-2008 |
Peter Zijlstra <a.p.zijlstra@chello.nl> |
hrtimer: clean up cpu->base locking tricks In order to more easily allow for the scheduler to use timers, clean up the locking a bit. Signed-off-by: Peter Zijlstra <a.p.zijlstra
hrtimer: clean up cpu->base locking tricks In order to more easily allow for the scheduler to use timers, clean up the locking a bit. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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